John harper



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J. HARPER.

PORTABLE SAPFOLD. No. 467,096. Patented Jan. 12,1892.

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PORTABLE SGAFFOLD. No. 467,096. Patented Jan. .12, 1892.

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JOHN HARPER, OF LONDON, ENGLAND.

PORTABLE SCAFFOLD.

SPECIFICATION forming part of Letters Patent No. 467,096, dated January12, 1892 Application iilecl October 2, 1891` Serial No. 407,528. (Nomodel.) Patented in England January 18, 1889, No. 9'7'7l I To all whom tmay concern:

Be it known that I. JOHN HARPER, engineer, of 129 Kings Road, CamdenTown, London, England, have invented a new and useful and an ImprovedPortable Scaold, (for which 1 have obtained Letters Patent in thefollowing country, namely: Great Britain, dated January 18, 1889, No. 977,) of which the following is a full, clear, and exact description.

This invention relates to a portable scaffold particularly adapted foruse in repairing, decorating, or cleaning buildings internally orexternally, as well as for constructional purposes, in lieu of theordinary cumbersome and expensive fixed scaffolding. This portablescaffolding is entirely self-con contained and is constructed inAsections, so that it may be adapted in height to the requirements lofthe work, and mounted on wheels in order that it may be easily movedfrom place to place, and it comprises a rising` platform iitted to moveup and down in the said framing, and provided with gear operated fromthe platform itself, whereby it may be raised to and maintained at therequired elevation.

Reference is to be had to the accompanying drawings, forming part ofthis specification, wherein- Figure 1 is an elevation of the lowermostsection of the framing, partly broken away to show the rising cage orplatform and its gearing. Fig. 2 is avertical cross-section of same.Fig. 3 is a plan of the cage or platform, and Fig. 4 is an under sideplan thereof.

The same letters of reference indicate like parts in all the figures. t

The main framing comprises a bottom fixed platform A, mounted on wheelsB, and four corner posts or columns C, fixed in shoes c, and constructedin lengths or sections halved together at their abutting ends andsecured by bolts, the foul` columns being braced together by diagonaltie rods or cramps D, furnished with screw-couplings at the middle. Uponan inner face'of each of the four posts O is fixed a rack E, these racksextending the whole height of the several lengths or sections, and withthese racks gear-pinions F on a pair of shafts G, mounted in brackets g,fixed to the under side of the iioor T of the cage or platform, theseshafts being geared by worm-gear H, with a transverse shaft I common toboth, and operated through bevelgear K from a winch-handle L, mounted ata convenient height to be worked by a person standing on the platform.Upon the other inner faces of the corner-posts C are guides M, ofdovetail or T section, with which engage shoes on the ends of theplatform, whereby all outward deflection of the corner posts isprevented, and the pinions F are held in gear with the racks E. Thetraveling wheels B, on which the framing is mounted, have peripheralholes n, in which engage locking-bolts O, mount-ed to slide in guides o,fixed to the under side of the base-platform A, the bolts being inpairs, each pair beingin alignment with a pair ofy the wheels B andbeing coupled to opposite arms l?, fixed on a common rock-shaft Q,operated by a lever-handle R, engaging with a rack S for the purpose ofholding the scaffold stationary when in use.

The cage comprises the platform T, uprights U, and cross-braces V, theplatform only engaging with the guides M, and the horizontality of theplatform being maintained by the coupling togetherof thetwo pairs ofpinions F, while the iixity of the cage at any height to which it may beraised is insured by the pinions being always in gear with the racks andby the use of worm-gear, which prevents the cage descending by its ownweight.

Having now particularly described and ascertained the nature of the saidinvention and in what manner the same is to be performed, I declare thatwhat I claim is- 1. The herein-described portable scaffold, consistingof the upright framing composed of corner-posts constructed in lengthsand erected on a wheeled base and braced together, as described, thesaid posts being provided with racks and guides, as described, incombination with a cage or platform adapted to be moved up and down thesaid guides, and provided with toothed gear engaging with the racks andcoupled by worm-gear to insure horizontality and xity of the cage, asspecified.

2. The combination, with the notched traveling wheels of theherein-described portable scaffold, of pairs of bolts adapted to engagetiierewith and coupled to and operated by L single hand-level', asspecified.

The foregoing specification of my improved portable scaffold signed byme this 9th day of September, lSOl.

JOHN HARPER.

